1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display which can reduce power consumption and prevent a reduction in the service life thereof.
2. Description of the Related Art
In general, a liquid crystal display includes a liquid crystal display panel and a backlight unit.
The liquid crystal panel includes a first substrate provided with field-generating electrodes such as pixel electrodes and common electrodes, a second substrate facing the first substrate, and a liquid crystal layer having liquid crystal molecules and formed between the first and second substrates. Voltages are applied to field-generating electrodes to generate an electric field in the liquid crystal layer having liquid crystal molecules, which determines the orientations of the liquid crystal molecules to control polarization of incident light, thereby displaying images. The liquid crystal panel of a liquid crystal display does not emit light by itself. The liquid crystal display requires the use of a separate backlight unit as a light source to supply light to the liquid crystal panel.
Backlight unit is roughly classified into an edge type backlight unit in which light is supplied from an edge area of a liquid crystal display, and a direct type backlight unit in which light is directly supplied from a rear surface of a liquid crystal display.
The edge type backlight unit includes a light source supplying light to the liquid crystal panel, a light guide plate guiding the light emitted from the light source to the liquid crystal panel, and optical sheets provided for improving optical properties of the light guided to the liquid crystal panel. The direct type backlight unit includes a diffusion plate provided for reducing bright rays of the light emitted from the light source, and optical sheets provided for improving optical properties of the light having passed through the diffusion plate. The light guide plate, diffusion plate and/or optical sheets may be received in a frame to then be aligned in the backlight unit.
In such a liquid crystal display, the light source can be driven by supplying a voltage from an inverter.